1 Covid patient in Karnataka infected 12 others: What it means amid 3rd wave threat

One Covid patient in Karnataka was spreading the infection to around 12 others in January this year, the state's serosurvey report, which has been published after much delay, has revealed. The findings of the second state serosurvey pertain to the beginning of the year, but the data might help epidemiologists to chart out the future course of action amid the threat of a third wave.

Here are the top 10 findings of the Karnataka serosurvey

1. Belagavi, Chamarajanagar, Mandya, Kodagu, Bagalkot Vijayapura, Ramanagara, Mysuru, Chitradurga reported a high transmission ratio.

2. Mysuru reported the highest seroprevalence, followed by Madhya, Kodagu, Chamarajanagar and Kolar.

Also Read: Around 250 cases in 5 days: Bengaluru sees spike of Covid cases among youth, children

3. Before the second wave struck, at least 1 in 6 people had Covid antibodies as the second serosurvey has found 15.6 per cent seroprevalence in the state.

4. People between the age of 50 and 59 had the highest protection against Covid In January-February. The lowest protection was observed among people between the ages of 18 years and 29 years.

5. At that time, Karnataka was far from attaining herd immunity or natural immunity.

6. The serosurvey addressed the issue of antibody waning which is the drop in natural antibodies with time. Candidates who took part in the first serosurvey were also called in the second one and it was found that half of them, who earlier had antibodies, lost these antibodies in the intervening gap of three months.

7. The study finds a near-0 prevalence of active cases during mid-February 2021, just before the second wave struck the state and the country.

8. The subsequent surge in Covid cases in Karnataka in April was due to a "mix of alpha, delta, and a huge susceptible population", Dr Giridhara R Babu, state advisory committee member, said.

9. The national serosurvey conducted by the Indian Council of Medical Research found that Karnataka has 69.8 per cent seroprevalence. 

10. This all-India survey was done during the second wave of the pandemic. Combining the findings of both, experts are now identifying the weak links to work on amid the threat of the third wave.